Fukushima power outage cause unknown: Tepco

Tokyo Electric Power Co said it still did not know what caused a power outage at four pools used to cool spent nuclear fuel at the crippled Fukushima Dai-Ichi plant.

According to a statement from Tokyo Electric, electricity was restored to all of the pools by 12 minutes after midnight. The outage, had disabled pumps at three of the plant's wrecked reactors' storage pools as also a shared pool, started at 6:57 pm on 18 March, according to the utility.

General manager, Masayuki Ono said at a briefing in Tokyo that the cause had not been found adding that 25 workers were investigating the outage, which was the longest and affected multiple units at the plant since the 11 March 2011, disaster that resulted in the three meltdowns.

The government said no radiation spikes had been recorded near the plant during the failure and the outage did not affect cooling systems for the plant's reactors. With no power to pump cooling water, uranium fuel rods stored in the pools could have heated up over days and released radiation.

There had been a meltdown of three reactors at the Dai-Ichi plant after it was hit by an earthquake and tsunami on 11 March two years ago, making it the world's worst nuclear accident since Chernobyl.

Last July around 170,000 people gathered at an anti-nuke rally in Tokyo's Yoyogi Park to demand that Japan phase out nuclear power in the wake of the Fukushima meltdown.

The Daily Beast reported that this year leading up to the second anniversary of the 11 March 2011 earthquake and tsunami that triggered the accident, there were about a tenth of that number at demonstrations, with ongoing weekly protests peaking at 5,000 or so, and some events drawing only a few hundred protesters.

According to Hiroaki Koide, assistant professor at Kyoto University Research Reactor Institute, after the Fukushima disaster, people worried much about nuclear power, but it was bound to happen that they gradually forget the (fear). He added, the Japanese government had also been trying to make the people forget, and the media now did not run reports as much as it used to do.

Also the country's limited energy alternatives were putting pressure on the country to restart the 50 or so reactors that were shut down two years ago and prime minister Shinzo Abe's new Liberal Democratic Party is less hstile towards nuclear energy.